A fuel injection system is known, from German Published Patent Appln. No. 29 08 095, for internal combustion engines having a plurality of fuel injectors, of which each, at its one end, is connected via a connection piece in a sealing manner to a barb nipple of an in-common, dimensionally stable, fuel distributor line, and has an orifice at another end. In this instance, each fuel injector is connected to the fuel distributor line by respectively one flexible, appropriately formed retaining clip which encompasses the fuel distributor and the fuel distributor line or the barb nipple. The retaining clip may be made of spring steel wire, in this case. The retaining clip may further be developed loop-shaped and be latched in on the barb nipple or the fuel distributor line with its loop portion facing away from the mounting points on the fuel injector
The fuel injection system known from German Published Patent Appln. No. 29 08 095 has the disadvantage that, because of the retaining clip, only an assurance against the release of the plug connection between the fuel distributor line and the fuel injectors and possibly more rapid assembly are achieved, for this, however, an additional component, namely the retaining clip being required and having to be mounted in addition. On account of the additionally required rigid insertion of the fuel injectors into inner bores of the barb nipples, what takes place in addition is the transmission of vibrations between the fuel injectors and the fuel distributor line. Consequently, the embodiment of the known fuel injection system is not suitable for applications in which such a vibration transmission is undesirable, based on noise development in connection with it, for example.
Especially in the case of electromagnetic high-pressure fuel injectors, which may be used in Otto engines having direct injection, a loud and disturbing contribution to the overall noise of the engine may occur, which has been described as valve ticking. Such valve ticking is created by the rapid opening and closing of the fuel injector, in which the valve needle is displaced with high dynamics to the respective end stops. The impact of the valve needle on the end stops leads to brief but very high contact forces which are transferred via a housing of the fuel injector to the cylinder head and to a fuel manifold in the form of structure-borne noise and vibrations. This leads to a strong noise development at the cylinder head and at the fuel manifold.